This invention relates to pressure sensitive hydrophone and more particularly to a decoupled pressure sensitive hydrophone which provides an undiminished acoustic sensitivity and simultaneously a reduced sensitivity to other disturbances induced in the material surrounding the hydrophone element.
In all underwater acoustic detection systems subjected to flow and/or vibration excitation, interfering noise is generated in the pressure sensitive hydrophone due to these sources of excitation in the structure immediately surrounding the hydrophone, which usually is some sort of flexible potting material. This causes degradation of acoustic signal detection capabilities of the detecting system. These sources of noise have long been recognized as a major problem in all underwater sound detecting systems used for a variety of purposes from detection of shipping to seismic streamer arrays used to survey the geological formations. In the past a variety of vibration isolation mounts and accerlation cancelling hydrophone designs have been attempted to minimize hydrophone response to undesired signals induced by flow and/or vibrational excitation. However, these attempts have involved costly and elaborate mounting schemes. However, no sucessful attempt has been made to construct a hydrophone that specifically minimizes the usual local stress concentrations in the potting material in the immediate vicinity of a hydrophone element when the hydrophone is located in an environment subject to flow and/or vibrational excitation. Furthermore, no sucessful attempt has been made to construct a hydrophone assembly that effectively decouples the hydrophone element from waves induced in the material surrounding the hydrophone element due to spurious mechanical excitation. It is therefore, desirable to have a hydrophone assembly which works with undiminished acoustic sensitivity, but which is effectively decoupled from these undesired noise signals.